SRA vs IRS on ATVs
By Midwest Traction on March 22, 2018
A quick Google search reveals that many off-roaders have asked this question: Is a solid rear axle better than an independent rear suspension? Why should I choose either one? We’ve compiled the research so you don’t have to sift through forums to find the details.
Solid Rear Axle
Solid rear axles are just that: solid. But where they excel in strength, they lack in flexibility.
This axle design has been around longer and is implemented on many work vehicles. A solid pipe connects both rear wheels. This means there are fewer moving parts, such as no stub axles with U-joints, which makes maintenance much easier. It reduces the risk of breakage while providing reliable stability. If you're in need of wheel bearing kits, we've got a selection of All Balls here.
SRAs have a lower rolling center, which decreases the likelihood of tipping over. They provide consistent, relatively unchanging ground clearance, so you’ll know exactly how much space you have between you and the ground no matter what. These are good for work, racing, and aggressive riding.
Because the rear wheels are connected by one long pipe, they don’t allow for much flexibility. When one tire crawls over an obstacle, the opposite is affected. While this may not harm the vehicle, it does impact rider comfort. You will experience more jostling with this axle design.
Verdict: If you’re in need of a work vehicle, or something a bit tougher to carry heavy loads, the SRA gets the job done reliably with little hassle.
Independent Rear Suspension
Independent rear suspension boosts comfort on rough terrain because the suspension is split.
When one tire crawls over a rock, the meat of the opposite maintains contact on the trail, creating a smoother ride over rough terrain. If you have back problems, this style tends to be easier on the joints and bones. The flexibility, comfort, and speed improve greatly with this type of rear suspension, making it great for trail riding, rock crawling, mud running, and rutted, rough trails.
Such a flexible suspension provides more ground clearance than an SRA, but the caveat here is that it doesn’t handle heavy loads. Your bodyweight will lower the clearance, along with any accessories or cargo you bring along. With more moving parts, you face a higher likelihood of mechanical issues, though regular inspection and maintenance should help combat this issue. If you're in need of replacement parts, you may be able to find some of them here. Raising the center of gravity does increase the possibility of rollover, and because the back bears less weight, the front end takes the brunt, especially on downhill stretches.
Verdict: If you’re using your ATV for play without many bells and whistles, the IRS will provide light, quick, comfortable performance.
Which to Pick?
That depends on your needs!
Flat surface riding is better for solid rear axles. Independent rear suspension performs better on a variety of bumpy terrain.
What are your thoughts? SRA or IRS? Tell us on social media.